Interference control in wireless communication

ABSTRACT

Wireless communication techniques for controlling radio frequency (RF) interference among a plurality of wireless devices operating at a location include monitoring RF utilization at the location, receiving a request from a wireless device indicating that the wireless device wishes to operate using an RF interference control service and communicating, in response to the received request from the wireless device, a software module that provides access point functionality to the wireless device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/887,039, filed May 3, 2013, which is incorporated by reference in itsentirety.

TECHNICAL FIELD

This patent document relates to wireless communications.

BACKGROUND

Many user devices such as smartphones, tablets, laptops, televisions,game consoles, and so on, are equipped with wireless communicationcapabilities to wirelessly connect to the Internet or othercommunication networks. The 802.11 suite of air interface standards(collectively called Wi-Fi) is the most common technology used forwireless connectivity and offers useful connectivity over distances ofup to a few hundred feet. With the proliferation of Wi-Fi enabled userdevices, the application layer bandwidth available per user device maybe unsatisfactory for some use cases.

While wireless standards have made progress to address such limitedbandwidth issues, publically available Wi-Fi infrastructures, e.g., thewireless access points or routers that connect the wireless network tothe Internet have primarily chosen to use simplistic Wi-Fi technologies.

Improvements to wireless communication techniques are desirable.

SUMMARY

This patent document discloses techniques for controlling interferenceamong user devices in a wireless communication network and can beimplemented to provide efficient use of available wireless spectrum at aparticular location for wireless communications. In some embodiments, aninterference controlling device can be deployed to operate side-by-sideexisting network infrastructure in a wireless location used by manyusers such as a shared or public Wi-Fi hotspot. In some embodiments, theinterference controlling device guides user devices to operate using aset of transmission/reception rules that ensure minimal interferenceamong devices with varying operational capabilities and bandwidthrequirements. In some embodiments, a software module may be downloadedto some user devices for providing the user devices additionalfunctionality to operate to mitigate the interference and efficientlyusing the spectrum at the location.

In one aspect, a method for providing wireless connectivity to a userdevice is disclosed. The method includes monitoring radio frequency (RF)characteristics of a location, receiving a connectivity request from auser device at the location, obtaining wireless operation capabilitiesof the user device, and providing, in response to the connectivityrequest and based on the wireless operation capabilities of the userdevice and the monitored RF characteristics of the location, wirelessoperation rules to the user device.

In another aspect, an apparatus for controlling radio frequency (RF)interference among a plurality of wireless devices operating at alocation is disclosed. The apparatus includes an interference monitoringmodule that monitors radio frequency utilization at the location, adevice registration module that receives a request from a wirelessdevice indicating that the wireless device wishes to operate using an RFinterference control service offered by the wireless communicationapparatus. The apparatus also includes a download module thatcommunicates, in response to the received request from the wirelessdevice, a software module that provides access point functionality tothe wireless device. In some embodiments, at least a portion of theapparatus is implemented in hardware.

These and other aspects and their implementations are described ingreater detail in the drawings, the description and the claims.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments described herein are illustrated by way of example and notlimitation in the figures of the accompanying drawings, in which:

FIG. 1 is an example of a wireless hotspot network.

FIG. 2 is an example of a process for operating a wireless hotspot bycontrolling radio frequency (RF) interference.

FIG. 3 is an example of the operation of a wireless device in acontrolled interference mode.

FIG. 4 is an example of an operation flowchart of a wirelesscommunication device.

FIGS. 5A, 5B and 5C pictorially depict examples of three differentdeployment scenarios for controlled interference operation of a wirelesshotspot.

FIG. 6 is an example of a process for providing wireless connectivity toa user device.

FIG. 7 shows an example of a block diagram of an apparatus forcontrolling radio frequency (RF) interference among a plurality ofwireless devices operating at a location.

FIG. 8 is an example of a process for wireless communications.

DETAILED DESCRIPTION

There is an ever-growing demand for wirelessly accessing the Internet orother communication networks at locations shared by many wireless userssuch as public or enterprise Wi-Fi locations at airports, restaurants,malls, offices, university campuses, company premises and so on. Usersserved by a shared wireless Wi-Fi hotspot may use different devices withwireless communication capabilities to wirelessly connect to theInternet or a communication network. Examples of such user devicesinclude smartphones, mp3 players, tablet computers, laptops, gamingdevices and others. Increasingly, wireless users accessing the Internetor a communication network tend to download or upload large files suchas video and audio files or streams and such wireless users increase theuser demand of the wireless bandwidth and Quality of Service at wirelesslocations that may not be easily available at crowded locations.

The 802.11 suite of standards for wireless connectivity using theIndustrial, Scientific and Medicinal (ISM) spectrum can provide wirelessaccess to the Internet or a network through devices and services,generally referred to as a “hotspot.” Over the past few years, severalnew techniques have been introduced to address the problem of crowdingof wireless spectrum. For example, the 802.11h variant of the 802.11wireless communication standard by Institute of Electrical andElectronics Engineers (IEEE) provides for dynamic frequency selection(DFS) and transmit power control (TPC) techniques to enable mitigationof inter-device interference and efficient utilization of wireless localarea network (WLAN) spectrum. Another technique, called “Wi-Fi Direct”allows for establishment of a peer to peer wireless connection betweenwireless devices.

Various public, enterprise or other hotspots shared by many users, whichprovide free or paid wireless services, may be limited in some serviceaspects, e.g., their wireless throughput and their wireless servicerange. As the number of users desiring to wirelessly connect to theInternet or other networks goes up, such public, enterprise or sharedhotspots face operational problems of not being able to meet thebandwidth and quality demand of the users.

A number of factors may contribute to the above operational problems.For example, some hotspots are deployed using pre-802.11h technologies,thereby not benefitting from the techniques described in thesetechnologies for efficient wireless communication. For example, WirelessAccess Point (WAP) routers operating in mixed-mode with slower speedclient devices connected often cause higher speed client capable devicesto suffer in throughput. This often happens with mixed 802.11g and802.11n devices on the same wireless network. For example, the aboveoperational problems may be in part caused by a lack of connectioninfrastructure management of some wireless hotspots on a pre-emptivebasis with variant client devices connected to deliver optimal wirelessthroughput. For another example, different wireless devices in use todaymay be equipped to operate based on different technology standards andthus have different wireless connectivity performance levels caused bywhether recent versions or legacy technology standards are used in suchdevices. For another example, many public and private hotspots havetypical simplistic WAP(s) rather than the enterprise WAP(s) and this useof the simplistic WAP(s) limits the throughput and functionality of suchhotspots because the simplistic WAPs may not implement bandwidthefficient techniques and some WAPs deployed today also may not haveability to operate in two different frequency bands. For anotherexample, 802.11n and 802.11ac routers provide dual band operation atboth the 2.4 GHz and 5 GHz bands and such dual band routers can reducethe reliance on the 2.4 GHz band which is overpopulated with userdevices, especially older wireless devices which tend to be only 2.4 GHzcapable and cannot operate in the 5 GHz range. Some newer devices mayalso be limited to a single frequency band (e.g., some recent tabletcomputers). Therefore, there may be issues with overloading a particularWi-Fi frequency band in some hotspots. For another example, the distancefrom client devices to the router can affect the throughput as well asthe capable wireless coverage. Wireless repeaters are often used to helpboost the signal when placed within proper geometric areas, however theyrequire additional infrastructure and overhead cost. For yet anotherexample, Wi-Fi is inefficient at managing interference (unlicensedband), especially among differently connected environments, Wi-Fi andNon-Wi-Fi (microwaves, cordless phones, baby monitors, wireless videocameras, Bluetooth) devices. The WAP will perform its best to minimizeinterference for already connected devices, besides the contention atthe media access control (MAC) PHY layer (e.g., collision avoidance).

The disclosed techniques can be used to address one or more of theabove-discussed problems and other performance issues in wirelessconnectivity at wireless hotpots serving wireless users. Using somedisclosed techniques, a service provider can be provide a wirelessconnectivity service for use in a public or other wireless accesslocation serving wireless users. The service can be deployed “side byside” existing access point hardware and backend equipment in locationssuch as cafes, stores, airports, office buildings, and so on. Usingdisclosed techniques, the service provider may control and managewireless operation of wireless devices to improve bandwidth availabilityand streamline bandwidth utilization. In some embodiments, the servicecan be embodied as a device that is reachable by user devices over awireless interface or an Internet Protocol (IP) connection. In someembodiments, the service may download a software module to a user deviceto control the user device's operational frequency band, Quality ofService of wireless communication, whether the wireless device acts as arelay for providing wireless connectivity to another wireless device,and so on.

In some implementations, a pre-emptive connection process can be used toprovide connectivity to a wireless device upon the device requesting tojoin a wireless network. In one advantageous aspect, enforcinginterference-reducing techniques during the admission process alleviatethe complexity of having to change operational parameters after wirelessconnectivity is established which could potentially disrupt applicationlayer communication. As further discussed below, techniques thatcontinuously monitor the RF environment at a location can beadvantageously used to reduce interference among wireless devices. Insome embodiments discussed below, training sequence initial input and alearned model of the environment may be used to continuously learn andadapt to RF environment. These and other useful techniques are furtherdescribed below.

The channel interference and congestion problem is typically experiencedin 802.11 variant networks rather than wireless 3G/4G operatingcarriers. Most 3G/4G carriers are charging for contracts based on amountof data usage, other than those consumers grandfathered into previouscontracts. Therefore Wi-Fi based networks are stressed even more forthese consumers. The use case can possibly be extended to multipleclient stations (STA) using a limited MiFi network device.

In some embodiments as discussed below, locations that consist of legacyWAP routers (in contrast with enterprise class WAPs that have additionalbandwidth management features and are more expensive dedicated functionWAP routers) may especially benefit from the disclosed techniques.

Assuming that the backend (e.g., line-based connection to the Internetat a hotspot) is relatively fixed, improvements can be made to managemultiple client (STA) connections for optimal network throughput. Thistakes a more pre-emptive approach, rather than reactive approach done bythe WAP. In addition, existing hardware and tools (e.g., a spectrumanalyzer) can be used to monitor the RF spectrum to reduce interference.However, this is done by post-analyzing the statistics and environment.Instead, the present document discloses techniques such as an autonomouspre-emptive adaptation of the connection process and continuousmonitoring of mixed STA environments to limit the overall interference.These techniques, in one advantageous aspect, can effectively mitigateinterference as it arises or before it arises.

Other alternatives (internet connection sharing (ICS), Tethering,Wireless Mesh Networking (WMN)) do not attempt to manage the sharedconnection based on the different client environments; instead focusingon the underlying technology mechanism. Tethering based solutions havetypically use Bluetooth Piconets and Legacy 802.11 ad-hoc networks.These technologies are not capable of providing the high bandwidthrequired by most application usages and have a limited address space (7in case of Bluetooth). Other research alternatives (WiFox) haveattempted to improve performance from the router component, rather thanthe STA, in order to flush queued data and prioritize some data over theother. Some enterprise router solutions even use smart antennasconsisting of beam forming to direct the signal, rather than usingtypical omnidirectional antennas. However these routers are nottypically found in most public sectors or even registered conferencesand trade shows. The techniques disclosed in the present documentprovide, among other benefits, a legacy WAP router the ability to reduceenvironment interference without additional hardware and infrastructure.

Dual Band (2.4 GHz/SGHz) devices may have the ability to perform asimilar function as a software access point (SoftAP). The SoftAP can beoffered as a downloadable service without any required manual setup orPIN acknowledgement. In some embodiments, the downloadable service mayallow each wireless station to additionally be operated in limitedaccess point mode.

In some embodiments, Wi-Fi Direct Power Management will allow eachSoftAP (Group Owner) to provide Opportunistic Power Save (OPS) andNotice of Absence (NoA) Protocols, thereby covering periods of powersavings when all the clients are sleeping and periods of absenceregardless of the clients association state.

FIG. 1 shows a wireless system deployment scenario 100. Multiplewireless devices 102, 104, 106, 108, 110, 112, 114, 116, 118, 122 and124 are wirelessly coupled to one or more other devices and coupled tothe Internet via the WAP 102. One non-Wi-Fi device 120 (e.g., a babymonitor) may also operate by using the ISM band.

Wireless devices 104, 108, 112, 114 are marked as “SoftAP” and mayimplement certain interference controlling operations, as furtherdescribed below. In some embodiments, SoftAPs may be able to operate inmultiple frequency bands. For example, two spectral frequency bands, a2.4 GHz band and a 5 GHz are available to Wi-Fi devices. Each frequencyband may include multiple RF channels on which a wireless network can beestablished. The SoftAPs 104, 108, 112, 114 may perform some (limited)communications functions (e.g., in accordance with the Wi-Fi Directstandard) generally performed by access points (AP) as defined in the802.11 standards suite.

SoftAP 104, 108 can be used to extend range of the WAP 102 to provideconnectivity to the station (STA) 110. In other words, the WAPtransmitter may not have to transmit power at as high a level todirectly reach the STA 110 but rather operate at a lower power level toreach the SoftAP 104 that relays communication between WAP 102 and STA110 via SoftAP 108. In some embodiments, the SoftAP functionality may beimplemented in a software-only implementation. In some embodiments,Wi-Fi Direct functionality may be implemented, which allows a station tobe in an AP mode, but allows devices to be connected to hard AP througha SoftAP. By contrast, in system 100, the SoftAP 108 is connected toanother SoftAP 104. For example, a laptop may be provided or activatedto act in the SoftAP mode, typically dual band operation (e.g., 2.4 GHzand 5 GHz operation). However, without the use of interference controlrules disclosed herein, throughput may go down in a mixed environmentwhen any device is allowed to join (e.g., by pulling network to 802.11g,or lower throughput). To mitigate this degradation, in some embodiments,all 802.11g devices may be directed to operate on 2.4 GHz and all802.11n devices may be directed to operate on 5 GHz frequency band.

In some embodiments, further described below, dual mode user devices(e.g., user devices that can simultaneously operate in two differentfrequency bands and are able to transfer data between the two airinterfaces) can be provided with SoftAP functionality by downloading asoftware module. In some embodiments, the software module may bedownloaded only when the target device reports that it is not inpossession of a previously downloaded software module. In someembodiments, when it is detected that the software module is already inpossession of the target device, a control message may be sent toactivate the software module that allows the target device to operate inSoftAP mode. In a typical scenario, proximity and channel selectioncriteria may be used to make a decision about which client device can beactivated. For example, in some embodiments, a wireless device that isfarther away may have a higher probability of activation as a SoftAPcompared to a near device. One reason may be that the reduction intransmitted power may be more significant when the device that isfarther away is able to act as an access point for nearby STAs.

Referring to FIG. 2, a wireless user device operating at a location andwishing to establish an Internet connection may first detect that ahotspot is available (206). For example, in many public locations,service operators such as AT&T Wireless provide a wireless access pointthat also functions as a router and provides internet connectivity overa backhaul network connected to the WAP. Upon establishing this initialconnection after associating with the hotspot (204), and during the use,the wireless user device may monitor bandwidth and quality of connection(e.g., latency, bandwidth etc.). When the device notices that thequality of connection has fallen below its expectation (e.g., jitteryvideo, high bit error rate, unsatisfactory web experience etc.) thedevice may disconnect from the hotspot (202). The wireless device maythen re-attempt to connect to a wireless service that is a “special”service (e.g., interference controlled service) instead of a hardrouter.

When the wireless device attempts to re-join the hotspot in theinterference controlled mode, the wireless device may communicate with ahotspot selector 210, sending a connection request 212 to operate undercontrol of the hotspot selector 210 which may also perform interferencecontrol operation. The hotspot selector 210 may exchange messages withthe wireless device to detect whether the device is able to act as aSoftAP. This may be based on broadcast capability information ordirectly exchange messages with the device. When it is determined thatthe wireless device cannot operate in SoftAP mode (208), the wirelessdevice is instructed to associate with the hotspot (204).

When it is determined that SoftAP operation is possible with thewireless device (214), the requesting wireless device is connected tothe hotspot selector 210 via a secure virtual private network toexchange messages (216). These messages include, e.g., interferencecontrol messages, spectral use reports, transmit power feedback and soon. When the user device decides to end the internet connectivitysession, the secure VPN is terminated and the wireless device isdisconnected from wireless service (202).

FIG. 3 represents a flowchart for a SoftAP detection and operationprocess 300.

SoftAP operation may include spectrum management. In some embodiments,802.11h may be followed to perform spectrum management. Examples oftechniques for spectrum management include dynamic channel managementand power control.

To exchange information about device capabilities and spectrummanagement, 802.11h beacon fields may be used. Alternatively, IP packets(e.g., application layer access established, followed by improvement)may be used. In some embodiments, each SoftAP will be responsible forbroadcasting information regarding its identity, capabilities, andenvironment surroundings. If the beacons and management frames do notinclude this information, then an IP broadcast or multicast groupaddressing will include these information elements (IE) in the payload.

At 302, the SoftAP receives capabilities of other devices in thenetwork. For example, other STAs may broadcast their operationalcapabilities (304). Also, other SoftAPs, if any, may broadcast theircapabilities (306). Based on the received device capabilities at thelocation and based on any additional site table (e.g., other wirelessdevices at the location), a determination is made (308) whether tooperate the SoftAP in a STA mode, or the independent basic service set(MSS) mode or in the Access Point mode. To make this determination, thetype of device on which the present SoftAP software module is running ischecked. For example, whether or not the device is capable of dual modeoperation, whether or not the device is able to operate in a QoS mode,and so on.

When operating in the SoftAP mode (316), received signal strengthindication (RSSI) measurements may be monitored (318) and input to atraining sequence module that learns the RF characteristics of thesystem in which the SoftAP is operating.

Further during the SoftAP operation, the device may use spectrummanagement techniques such as defined in the 802.11h standard. Forexample, period measurement reports may be requested and received (328).Based on these reports, a determination may be made about whether or notto perform a band shift (330), e.g., operate in 5 GHz mode only.

The periodic measurement reports may be generated based on RFmeasurements taken during action frames (e.g., management transmissionframes) or during quiet periods in which no device is transmitting onthe medium. Based on action frame measurements, transmit power controlreports may be received (332). These reports may be used to adaptchannel transmit power control (334), including, e.g., calculating pathloss and link margin estimates for communication channels to other STAsor SoftAPs.

Based on the measurements during quite period, amount of interference ona channel (e.g., caused by a neighboring access point) can be measured(336). A determination can be made about how much channel capacity isbeing utilized (338). When, e.g., it is determined that a given RFchannel is being used near maximum capacity, then either a new WAP isselected for the data traffic and some traffic is off-loaded to the newWAP (which can establish its network on a different RF channel).Alternatively, the frequency of operation may be shifted for devicescurrently in the network (340).

Furthermore, DFS measurement reports may be processed (342) to determineif channel interference from nearby channels is above an unacceptablethreshold (344) and a channel switch may be performed (346) byannouncing the channel switch (348), followed by moving to a newoperational frequency (channel).

The measurement reports gathered from measurements made using actionframes and during quiet period are input to the training sequence modulewhich creates a model that can be used to build a site table that listslocations and channel characteristics between location pairs (322). Itmay be possible to draw inferences about the RF environment. Forexample, it may be possible to determine whether two different locationshave a line-of-sight (LOS) channel (324) or whether there is an RFbarrier between the two locations (e.g., when path loss is 6 dB orgreater). The selection may this be performed by preferring an LOSchannel for operation of the wireless connection (326).

In some embodiments, a SoftAP policy discovery mechanism is based onnumerous parameters, one or more of which may be implemented in a givenembodiment, such as detection of b/g/n type STA based on Supported Ratesand High Throughput (HT) Capabilities; Channel Interference [Overlappingvs. Non-overlapping]; Channel Switch Inclusion [Channel SwitchAnnouncement] and Dynamic Frequency Selection (DFS); Channel Quality,Capacity and Utilization metrics; RSSI (S/N): Signal power—Noise Floorratio; High Throughput Capabilities (HT); Specific to 802.11n devices;Transmit Power Control (TPC) Request/Response Reports; MeasurementReports (e.g., Action Frame, 802.11h); Power Constraint (e.g.,Advertised as Min/Max capable power in conjunction with regulatoryconstraints); Neighbor Reports from other STA(s) and SoftAP(s); PathLoss Calculation Estimate (e.g., Transmit power reported vs. actualreceived power); Quality of Service (QoS) Access Category Type ofService (TOS) per 802.11e/WMM (Video, Voice); and Location andenvironment approximation (e.g., causing the SoftAP to make a selectionaway from physical barriers, if any are detected).

In some embodiments, communications with the STA 106 can be made tolimit mixed-mode operation and direct traffic to the less overpopulatedband, as newer routers support multiple radios.

QoS data (e.g. voice, video) can be directed to the less overpopulatedband and possible a different AP if multiple AP(s) are available in thevicinity.

If applicable, STAs can negotiate/exchange optimal preferred settings(channel assignments, non-overlapping channels) to the router.

STAs further away or out of coverage range or transmission range canconnect to a radiating wireless SoftAP that acts as a relay device, whenpreviously they would be unable to gain favorable coverage.

Therefore, a legacy WAP deployed in a location serviced by a serviceoperator can become a smart WAP that can mitigate interference byperforming channel selection and transmit power control and additionalcontrol functionality without an additional upgrade on the backend orhardware infrastructure. In one beneficial aspect, this solution allowsenhanced capabilities to be achieved while still being vendor agnosticand saving cost.

In some embodiments, if currently associated SoftAP moves away from thelocation, a handoff to another SoftAP may be performed for wirelessdevices that used the currently associated SoftAP for their internetconnectivity. For example, this can be accomplished by monitoring a timewindow and when no broadcast messages are received from a SoftAP, then ahandoff is triggered to another SoftAP.

In some embodiments, RF barriers (e.g. walls, insulation, metal,concrete) can be avoided and selection will be prioritized to Line ofSight (LOS) and centered location areas.

In some embodiments, a reduction in number of devices sharing aparticular radio band on the AP may be performed to reduce interference.

In some embodiments, measurement reports include Action frames from oneSoftAP and/or STA to measure the quality of another, thereby providingneighbor reports.

In some embodiments, signal gain is increased by controlling theenvironment and noise having less impact.

In some embodiments, minimum and maximum RF power levels conforming toregulatory constraints may be enforced. In some embodiments, localtransmit power may be calculated to reduce interference and limit orincrease ranging.

In some embodiments, a measurement and a change of link margin andacceptable attenuation may be used to determine an acceptable powerlevel before communications link no longer functions. Typically, a WAPwill have reduced power to reach nearby STA(s), as further STA(s) willbe communicating with those nearer STA(s) functioning as a SoftAP.

In some embodiments, SoftAP positioning may be estimated based onpath-loss model to estimate the relational distance from other STA(s)and the best selection of one SoftAP over another.

In some embodiments, a channel that shows other co-channel RF activitymay be avoided. In Wi-Fi, a number of non-overlapping channels areavailable for operation (2.4 GHz: 1, 6, 11, channels and 5 GHz: 23number of channels in the U.S.).

In some embodiments, channel Selection is based on advertised SupportedChannels, Measurement, signal strengths, measuring of non-overlappingchannels to determine the channel quality.

In some embodiments, a change in the operational channel is supported byall already connected STA(s) (i.e., do not move to a channel that willresult in an STA being dropped from the network).

In some embodiments, channel changing may be limited in environmentswith many SoftAP(s) functioning, because unused channels may not bereadily available. However 802.11n devices may change channels morefrequently to perform channel bonding to increase throughput ofoperation.

In some implementations, QoS capable devices may be moved to a singlechannel or frequency band so that these devices can enjoy high qualityvideo sessions. In some embodiments, a QoS STA is directed using aChannel Notification message to switch channel.

With reference to FIG. 4, If RF Interference is detected (Wi-Fi andNon-Wi-Fi), a wireless device may be controlled (402) to move to anotherAP (404) or shift away from the band (408) occupying that same frequencyspectrum. The shift to another AP may not be possible if the hotspotoperates using a single WAP (406), in which case, the wireless networkmay be shifted to another frequency band.

FIGS. 5A, 5B and 5C depict three alternate deployment scenarios in whichan interference controlled wireless network can be operated.

FIG. 5A depicts a deployment example in which a wireless local areanetwork 502 forms a hotspot having WAP 102 as the router that providesinternet connectivity to wireless devices 506 coupled to the WLAN 502.The interference controlling device 504 is in communication with thewireless devices 506 using connectivity from the WLAN 502.

Compared to FIG. 5A, in the deployment depicted in FIG. 5B, theinterference controlling device is located at the location of the WAP102, but is communicating with the wireless devices 506 via a wiredconnection to the backhaul Internet connectivity of the WAP 102. In thisdeployment, the interference controlling device 504 may not havewireless communication capability. In other words, for monitoring RFinterference and spectral use in the WLAN 502, the interferencecontrolling device 504 may strictly depend on reports received fromwireless devices 506.

In FIG. 5C, the interference controlling device 504 is coupled to theWLAN 502 over the internet 508, through the WAP 102. In this deployment,the interference controlling device 504 may not be physically present atthe location of the hotspot, but may be elsewhere (e.g., at a serviceprovider's facility). The interference controlling device 504 may be incommunication with a sensory module 510 that may be a stand-alonemodule, or a part of the WAP 102. The sensory module 510 may beconfigured to provide RF characteristics of the hotspot to theinterference controlling device 504.

FIG. 6 is a flowchart representation of a process 600 of providingwireless connectivity to a user device.

At 602, the process 600 monitors radio frequency (RF) characteristics ofa location. In some embodiments, 602 includes monitoring a number ofdevices operating on each RF transmission channel available at thelocation and monitoring a type of air interface protocol (e.g., 802.11)used by each wireless device operating at the location.

In some implementations, 602 includes obtaining information indicativeof a transmission power level used by the user device and other userdevices operating at the location. As previously described, fields usedby 802.11h beacon frames may be used for obtaining the information. Insome embodiments, physical barriers causing RF signal attenuation at thelocation may be estimated. For example, a threshold may be used todetermine the presence of a physical barrier (e.g., 3 dB or 6 dBadditional attenuation in the link that is not due to the distancebetween the transmitter/receiver pair). In some embodiments, theestimation of the physical barrier is used to control wireless operationrules of another wireless device (e.g., transmit power or whichfrequency band the device should operate in, and so on).

At 604, the process 600 receives a connectivity request from a userdevice at the location.

At 606, the process 600 obtains wireless operation capabilities of theuser device. In some embodiments, the information obtained may includeinformation about whether or not the user device is capable of adual-band operation.

At 608, the process 600 provides, in response to the connectivityrequest and based on the wireless operation capabilities of the userdevice and the monitored RF characteristics of the location, wirelessoperation rules to the user device. In some implementations, theproviding the wireless operation rules includes determining whether theuser device is operable in an access point mode in which the user deviceperforms upstream and downstream data transmissions with another userdevice and downloading a software module to the user device to providethe access point mode capability to the user device.

In some embodiments, the process 600 further includes receiving aninterference report from the user device and updating the monitored RFcharacteristics of the location based on the received interferencereport.

In some embodiments, the process 600 includes obtaining a first uniqueidentification for a first wireless access point providing Internetconnectivity at the location and a second unique identification for asecond wireless access point providing Internet connectivity at thelocation wherein the wireless operation rules includes the first uniqueidentification or the second unique identification, thereby instructingthe wireless device to establish connectivity with the first wirelessaccess point or the second wireless access point. The uniqueidentification could, e.g., be the medium access control (MAC) serialnumber of the device and may further include the subscriber service setid (SSID) of the wireless access point.

FIG. 7 is a block diagram representation of an apparatus 700 forcontrolling radio frequency (RF) interference among a plurality ofwireless devices operating at a location. In some embodiments, theapparatus operates to control RF interference without providing internetconnectivity and without providing data traffic routing capability tothe plurality of wireless devices.

The module 702 (e.g., interference monitoring module) is for monitoringradio frequency utilization at the location. In some embodiments, theinterference monitoring module monitors RF utilization at the locationusing a radio frequency receiver module that receives wireless signalsto monitor spectral usage or a spectrum use receive module that receivesreports from the wireless devices, the reports comprising informationabout spectral interference measured at the wireless devices.

The module 704 (e.g., a device registration module) is for receives arequest from a wireless device indicating that the wireless devicewishes to operate using an RF interference control service offered bythe wireless communication apparatus.

The module 706 (e.g., a download module) is for communicating, inresponse to the received request from the wireless device, a softwaremodule that provides access point functionality to the wireless device.

In some embodiments, the apparatus 700 further includes a channelselection module that assigns, for each registered wireless device, anRF channel for operation for the corresponding registered wirelessdevice. In some embodiments, the channel selection module is furtherconfigured to assign the RF channel for operation based on a Quality ofService desired by the registered wireless device and an air interfaceprotocol version capability of the registered wireless device. In someembodiments, the apparatus 700 may be able to tune and operate ondifferent RF channels or frequency bands, but, at any given time, mayonly be able to operate in a single frequency band and RF channel. Insome embodiments, the apparatus 700 may have the ability tosimultaneously operate on multiple channels (e.g., channel bonding toincrease throughput).

In some embodiments, the apparatus 700 further includes a spectrum usereceive module that receives reports from the wireless devices, thereports comprising information about spectral interference measured atthe wireless devices, including transmission power used by the wirelessdevices and a topology determination module that determines, based onthe received reports from the wireless devices, an RF obstruction at thelocation. In some embodiments, a relay configuration module thatcontrols operation of one of the wireless devices to operate in a relaymode to provide wireless connectivity to another one of the wirelessdevices across the RF obstruction is further included. In someembodiments, the relay configuration module controls operation of one ofthe wireless devices to operate in a relay mode to provide wirelessconnectivity to another one of the wireless devices that is outside atransmission range of the access point. The transmission range may beincreased such that the relay module is within the transmission range ofthe wireless access point, and the wireless device is within thetransmission range of the relay device, but the wireless device isoutside of the transmission range of the wireless access point.

FIG. 8 depicts a flowchart of a process 800 of wireless communication.The process 800 may be implemented on a wireless device that is a userequipment such as a smartphone or a tablet computer.

At 802, the process 800 requests admission to a wireless network forestablishing an initial Internet connectivity.

At 804, the process 800 monitors, upon admission, a Quality of Service(QoS) of the initial Internet connectivity;

At 806, the process 800 exits the wireless network when the QoS fallsbelow an acceptability threshold; and

At 808, the process 800 requests re-establishing a subsequent Internetconnectivity over the wireless network, after the exiting, using aninterference controlled operational mode that was not used forestablishing the initial Internet connectivity.

In some embodiments, the process 800 further includes receiving asoftware module and executing the software module to implement theinterference controlled operational mode when transmitting and receivingdata in the wireless network.

In some embodiments, the process 800 further includes transmittinginformation indicative of an amount of radio frequency interferenceestimated on a wireless channel of operation.

It will be appreciated that techniques are provided for providingwireless connectivity without having to upgrade backend infrastructure.In some embodiments, the presence of a physical barrier may beindicative of a steep increase in RF power level for maintainingconnectivity between two wireless devices. In some implementations,non-Wi-Fi interference may be mitigated by channel selection or SoftAPreassignment. In some embodiments, the wireless connectivity to anaccess point may be provided through multiple hops (relays).

It will further be appreciated that the disclosed techniques enable theestablishment of a wireless local area network in which some wirelessdevices are configured to act as access points and learning RFcharacteristics at a site (e.g., via a site table) to assign a frequencyband of operation to other wireless devices in the network.

The disclosed and other embodiments, modules and the functionaloperations described in this document can be implemented in digitalelectronic circuitry, or in computer software, firmware, or hardware,including the structures disclosed in this document and their structuralequivalents, or in combinations of one or more of them. The disclosedand other embodiments can be implemented as one or more computer programproducts, i.e., one or more modules of computer program instructionsencoded on a computer readable medium for execution by, or to controlthe operation of, data processing apparatus. The computer readablemedium can be a machine-readable storage device, a machine-readablestorage substrate, a memory device, a composition of matter effecting amachine-readable propagated signal, or a combination of one or morethem. The term “data processing apparatus” encompasses all apparatus,devices, and machines for processing data, including by way of example aprogrammable processor, a computer, or multiple processors or computers.The apparatus can include, in addition to hardware, code that creates anexecution environment for the computer program in question, e.g., codethat constitutes processor firmware, a protocol stack, a databasemanagement system, an operating system, or a combination of one or moreof them. A propagated signal is an artificially generated signal, e.g.,a machine-generated electrical, optical, or electromagnetic signal, thatis generated to encode information for transmission to suitable receiverapparatus.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, and it can bedeployed in any form, including as a stand alone program or as a module,component, subroutine, or other unit suitable for use in a computingenvironment. A computer program does not necessarily correspond to afile in a file system. A program can be stored in a portion of a filethat holds other programs or data (e.g., one or more scripts stored in amarkup language document), in a single file dedicated to the program inquestion, or in multiple coordinated files (e.g., files that store oneor more modules, sub programs, or portions of code). A computer programcan be deployed to be executed on one computer or on multiple computersthat are located at one site or distributed across multiple sites andinterconnected by a communication network.

The processes and logic flows described in this document can beperformed by one or more programmable processors executing one or morecomputer programs to perform functions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read only memory ora random access memory or both. The essential elements of a computer area processor for performing instructions and one or more memory devicesfor storing instructions and data. Generally, a computer will alsoinclude, or be operatively coupled to receive data from or transfer datato, or both, one or more mass storage devices for storing data, e.g.,magnetic, magneto optical disks, or optical disks. However, a computerneed not have such devices. Computer readable media suitable for storingcomputer program instructions and data include all forms of non-volatilememory, media and memory devices, including by way of examplesemiconductor memory devices, e.g., EPROM, EEPROM, and flash memorydevices; magnetic disks, e.g., internal hard disks or removable disks;magneto optical disks; and CD ROM and DVD-ROM disks. The processor andthe memory can be supplemented by, or incorporated in, special purposelogic circuitry.

While this patent document contains many specifics, these should not beconstrued as limitations on the scope of an invention that is claimed orof what may be claimed, but rather as descriptions of features specificto particular embodiments. Certain features that are described in thisdocument in the context of separate embodiments can also be implementedin combination in a single embodiment. Conversely, various features thatare described in the context of a single embodiment can also beimplemented in multiple embodiments separately or in any suitablesub-combination. Moreover, although features may be described above asacting in certain combinations and even initially claimed as such, oneor more features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asub-combination or a variation of a sub-combination. Similarly, whileoperations are depicted in the drawings in a particular order, thisshould not be understood as requiring that such operations be performedin the particular order shown or in sequential order, or that allillustrated operations be performed, to achieve desirable results.

Only a few examples and implementations are disclosed. Variations,modifications, and enhancements to the described examples andimplementations and other implementations can be made based on what isdisclosed.

The invention claimed is:
 1. A first apparatus for coping with Wi-Firadio frequency interference among a plurality of wireless devicesoperating at a location, the first apparatus comprising: a receiver; atransmitter; and a data processing apparatus connected to the receiverand the transmitter; wherein the data processing apparatus is configuredto receive a report from a second apparatus; based at least in part oninformation in the report, make a determination to perform a channelswitch for at least one wireless device currently in radio frequencycommunication with the first apparatus on a radio frequency channel; andannounce the channel switch to the wireless device; and wherein thefirst apparatus is configured to: connect to the Internet and to operateto cope with Wi-Fi radio frequency interference while connected to theInternet without providing Internet connectivity and without providingdata traffic routing capability to the plurality of wireless devices. 2.The first apparatus of claim 1, wherein the data processing apparatus isfurther configured to request the report from the second apparatus. 3.The first apparatus of claim 1, wherein the report includes aninterference on a radio frequency channel as measured by the secondapparatus.
 4. The first apparatus of claim 3, wherein the determinationis based at least in part on information in the report pertaining to oneor more measurements taken by the second apparatus indicative of theinterference on the radio frequency channel.
 5. The first apparatus ofclaim 1, wherein the second apparatus is configured to act as an accesspoint.
 6. A method for coping with Wi-Fi radio frequency interferenceamong a plurality of wireless devices operating at a location, themethod comprising: receiving, by a first apparatus including a dataprocessing apparatus connected to a receiver and a transmitter, a reportfrom a second apparatus; making, by the first apparatus based at leastin part on information in the report, a determination to perform achannel switch for at least one wireless device currently in radiofrequency communication with the first apparatus on a radio frequencychannel; and announcing the channel switch to the wireless device;wherein the first apparatus is configured to connect to the Internet andto operate to cope with Wi-Fi radio frequency interference whileconnected to the Internet without providing Internet connectivity andwithout providing data traffic routing capability to the plurality ofwireless devices.
 7. The method of claim 6, wherein the data processingapparatus is further configured to request the report from the secondapparatus.
 8. The method of claim 6, wherein the report includes aninterference on a radio frequency channel as measured by the secondapparatus.
 9. The method of claim 8, wherein the determination is basedat least in part on information in the report pertaining to measurementstaken by the second apparatus indicative of the interference on theradio frequency channel.
 10. The method of claim 6, wherein the secondapparatus is configured to act as an access point.
 11. A first apparatusfor communicating with a plurality of wireless devices operating at alocation, the first apparatus comprising: a receiver; a transmitter; anda data processing apparatus connected to the receiver and thetransmitter; wherein the data processing apparatus is configured toreceive a report from a second apparatus; based at least in part oninformation in the report, make a determination to offload a portion ofthe traffic on a radio frequency channel from a first access point to adifferent access point; select a second access point to offload theportion of the traffic on the radio frequency channel from the firstaccess point, wherein the second access point is different from thefirst access point; and offload the portion of the traffic on the radiofrequency channel from the first access point to the second accesspoint; and wherein the control apparatus is configured to connect to theInternet and to operate to cope with Wi-Fi radio frequency interferencewhile connected to the Internet without providing Internet connectivityand without providing data traffic routing capability to the pluralityof wireless devices.
 12. The control apparatus of claim 11, wherein thedata processing apparatus is further configured to request the reportfrom the second apparatus.
 13. The control apparatus of claim 11,wherein the report includes an interference on a radio frequency channelas measured by the second apparatus.
 14. The control apparatus of claim11, wherein the determination is based at least in part on informationin the report pertaining to measurements taken by the second apparatusindicative of channel capacity being utilized on the radio frequencychannel.
 15. The control apparatus of claim 11, wherein the secondapparatus is selected as the new access point.
 16. A method for copingwith Wi-Fi radio frequency interference among a plurality of wirelessdevices operating at a location, the method comprising: receiving, by acontrol apparatus including a data processing apparatus connected to areceiver and a transmitter, a report from a second apparatus; making, bythe control apparatus based at least in part on information in thereport, a determination that a portion of the traffic on a radiofrequency channel from a first access point should be offloaded to adifferent access point; selecting a second access point for the portionof the traffic on the radio frequency channel from the first accesspoint, wherein the second access point is different from the firstaccess point; and offload the portion of the traffic on the radiofrequency channel from the first access point to the second accesspoint; wherein the control apparatus is configured to connect to theInternet and to operate to cope with Wi-Fi radio frequency interferencewhile connected to the Internet without providing Internet connectivityand without providing data traffic routing capability to the pluralityof wireless devices.
 17. The method of claim 16, wherein the dataprocessing apparatus is further configured to request the report fromthe second apparatus.
 18. The method of claim 16, wherein the reportincludes an interference on a radio frequency channel as measured by thesecond apparatus.
 19. The method of claim 16, wherein the determinationis based at least in part on information in the report pertaining tomeasurements taken by the second apparatus indicative of channelcapacity being utilized on the radio frequency channel.
 20. The methodof claim 16, wherein the second apparatus is selected as the new accesspoint.